Lamp support arm



FIG. 1 is a right side elevational view of the lamp support arm in accordance with our design, illustrated in an environment of a lamp;

FIG. 2 is a top plan view of the lamp support arm in accordance with our design;

FIG. 3 is a rear side elevational view of the lamp support arm in accordance with our design;

FIG. 4 is a right side elevational, view of the lamp support arm in accordance with our design the left side being a mirror image thereof;

FIG. 5 is a front side elevational view of the lamp support arm in accordance with our design; and,

FIG. 6 is a bottom plan view of the lamp support arm in accordance with our design.

The broken lines show the environment in which the article is used and are not considered part of the design claimed. 

The ornamental design for the lamp support arm, as shown and described. 